Municipal　wastewater　treatment　suffers　the　general　problems　of　poor　denitrification　and　low　phosphorus　removal　caused　by　insufficient　carbon　sources.　Thus,　a　baffled　reactor　was　developed　to　provide　additional　carbon　by　hydrolysis　and　acidification　of　the　primary　sludge　in　the　A(2)/O　process　in　order　to　treat　low　C/N　ratio　wastewater.　The　effects　on　denitrification　and　phosphorus　removal　were　evaluated.　The　results　showed　that　C-TN,　C-TP,　C-COD,　and　CNH4+-N　in　the　effluent　were　concentrated　at　17,　0.5,　30,　and　1.6　mg/L,　respectively,　while　the　removal　efficiencies　rose　to　69.6,　92.5,　88,　and　96.7%,　respectively,　while　dosing　acidified　primary　sedimentation　sludge.　Compared　with　control　groups　that　did　not　receive　acidification　liquid,　C-TN,　C-TP,　and　CNH4+-N　of　the　effluent　were　decreased　by　8.7,　1.3,　and　0.7　mg/L,　respectively,　and　the　removal　efficiencies　were　correspondingly　increased　by　15.6,　22.5,　and　1.7%,　respectively.　These　data　demonstrated　that　adding　acidified　primary　sludge　effectively　improved　the　removal　of　nitrogen　and　phosphorus　nutrients.